Program transmission over wires



Nav. 16 1926.

J. F. TOOMEY ET Al.

PROGRAM TRANSMISSION OVER WIRES Filed Nov'. 11. '1922 2 Sheets-Sheet 2 J ATTORNEY Patented Nov. 16, i926.

JOHN' F. TOOMEY AND HENRY E. PHEJPS, OF NEW YORK, N, Y., ASSGNORS TO AMER/- OAN TELEPHONE AND TELEGRAPH COMPANY, A CORPORATION kCI'F NEW YORK.

PROGRAM TBANSMI-SSOT OVER WIRES.

Application filed Novemberll, i922.; Serial No. 600,356.

This invention relates tol systems of communication and more particularly to systems for disseminating news, information, music or the like.

`Various schemes have been proposed heretofore for program transmission. The only one of these schemes which has been eX- ploited to any extent is radio broadcasting, that is, the broadcasting of news, information or entertainment by means of radio telephone equipment so that persons provided with suitable radio .receiving sets tuned to the proper wave length may receive the transmitted entertainment or the like.

Realizing the inherent limitations of radio broadcasting, proposals have been madeto use existing wire systems, such as telephone, telegraph or power networks for program distribution purposes by transmitting carrier frequencies over such existing kpower or communication lines. Such a method, however, would be extremely expensive as well as complicated, as it involves a very considerable reorganization of the telephone kplant or power plant, and requires the use of quite complicated and expensive apparatus.

The ordinary telephone plant, however, offers unusual facilities for program distribution purposes by the use Yof ordinary telephonie methods and without the employment of any high frequency or carrier methods of signaling. When it is realized that the average subscribers telephone set is in use for telephonie purposes'only during an extremely small part of the time itbecomes apparent at once that if the telephone line, during its idle periods, could be used for disseminating news, information or entertainment, the plant could be used much more economically and the information or the like to be vdistributed could be transmitted to the subscriber in the simplest manner possible. It may further be observed that the average subscriber to a distributing service, particularly a service for distributing entertainment, would only desire to avail himself of the service during the late afternoon or during thev evening, at which times the average subscribers telephone is only used for social purposes and is rarely or never used for business calls. v

Having these circumstances in mind, it is scriber.

proposed by this invention to provide simple, practical and yeconomical arrangements by Vwhich news, information, music or other forms of entertainment may be transmitted vat ordinary telephonic frequencies from a central program distributing stat-ion over subscribers telephone lines. It is also proposed by this invention to provide a system whereby the telephone subscriber may receive the entertainment service without interferingin any way with the use of his linev for ordinary telephone purposes. This invention alsor renders available a program distributing system in which the apparatus not only at the central station but more particularly at the subscribers station, will be extremely simple and economical and yet efficient. 4 y Y It is, of course, possible to so arrange the circuit for accomplishing these results that the connection and disconnection of the program apparatusfto the subscribers line willy be directly under the control of the sub- The circuit arrangement of the present invention, however, is such that the programequipment may be connected to the subscribers line by an operator at a special switching point. This enables the subscriber either' to contract for the entertainment service for certain periods of the day or he may obtain the service at any time of the day by calling theoperator andasking for it.

' The invention may now be more fully understood by reference to the following detailed description thereof when read in connection with the accompanying drawing, in

which Figure l is a circuit arrangement embodying the principles of the invention and Figs. 2 and 3 illustrate modifications.

Referring .to Fig. l, L designates an ordinary telephone subscribers line terminat-y ing at one end at a subscribers station A and at the other ina central office B. At the station A, the kusual form of telephone set is provided for ordinary telephonie purposes and a supplemental key K is provided for associating with theline a program receiving equipment comprising a loud speaking receiver 11 and other apparatus to be described later.

lAt the central station B, the line terminates at an operators position of the switchaV cord or trunk C terminating in a plug P.

board in the usual type of switching jack J, whereby telephonie communication may be established througlr the cordcircuit between` the line L and *other lines'ytermmating at the exchange. Normally, the line is connected with the jack J over 'the contacts ot the marginal relay 12, which, whenenergleed, isl so arranged as to disconnectthe linetroin the jack J and connect it to a Jack J through which a connection may be made to a program station (not shown) through As the program station Ais not normally connected tothe Vline L, the subscriber, m order to avail :himself ot 'the service, may

either-,have a contract arrangement where! by the special operator in charge of the program equipment may connect the program station vto the hne during a given vaeriod of the day by inserting 'the plug in the jack J orthe subscriber may call up the'op'erator at the regular switchboard in the usual manner and the operator,

upon being informed that a program connection is desired, may instruct the Special operator to insert the plug Pv in the jack J. ln vvorder Vto signal the regular f operator the vusual line relay LR `is provided at `the regular switchboard.` This line relay LP is' marginal and does not operate through the highimpedance connection established by the key K, andl will only -opcrate wheny the' line is closed through the low impedance telephone set 1() by-taking the receiver' from the switchhook. A similar line relay LR is provided in connection with the cord Icircuit C and this second line relay jointly controls the circuit of the marginal Vrelay 1Q with thecut-otl' relay COR vat vthe regular operator-s position:

At the subscribers station, the transiformer 14, which serves toassociate the loud' speaking receiver 11 with the line, is provided with a condenser shunted by the high resistance winding'ot the polarv'relay PR. Owing to the high resistance of the latter,

whenthe key K is thrown, insullicient cur# rent flows through the bridge, including the windings ot the line relays LR and LR',-

as the case may be, to operate said relays. 'l`hepolar relay PR controls a relay' 16, whereby Athe loud speaking receiver 11 may be disconnected from the line even though vthe V'key K is actuated. The p olar relay PR `the plug of the cord circuit C into the jack to' establish an ordinary telephone ,con-

nection. Ay low resistance relay 17 is included in series with the subscribers set 10,

r)This arrangement is provided so that theprogram receiving equipment will be disconnected lunder these circumstances even though the subscriber should 'fail to restore the-key K. i v

The' detailed operation is as follows: Assuming that the subscriber at station fA desires to receive `the entertainment `service he removes the receiver from the switchhook, therebyelosing the line circuit to operate the line relay LR, the line relay in turn causing .the line lamp to glow. 'Phe relay 17 at the subscribers stationis opi-atedl in series with the line relay LR and functions to disconnectvthe loud speaking (receiver 11 and associated equipment .from the line independently of thekey K. When the `operator at the regularswitchboard observes Vthe call signal, she vwill'answer the call by inserting the' plug of thecord eircuit C in the jack J thereby energizing the cut-ottq relay COR, which disconnectsthe Vline relay LR from the linev andv `extinguishes the. signal. Upon being informed that' a program connection is'ldesired the operator will inform a special operatorv at the program multiple thatav program ,con-- neetion is desired uponthis particular line. V In practice, different programs may be transmitted at the same ytime and'iffthesubscriber has asked :l-'or connection with'a station sending out a particular program, the operator at the program multiplewill insert the plug P of the cord circuit C connected with the proper progranr station into the jack J. lar switchboard position inthe `meantime Lwill instructthe subscriber to hang lup his rl`he operator at the regureceiver and will withdraw the plug P from the jack J. The eut-.ott relay CCR is deenergized upon withdrawing the plug P and acircuit is Vcompleted over the right-hand back contact the cut-oil relay COR through the winding of the marginal relay 12, over the sleeve conductors vof the jack J and the plug P and back contact of the marginal relay LR to battery.V The marginal relay 12 is now energized and discon- Y nects the line L from the jack J and connects itA to the jack yJ so that a connection is; extended over the cord circuit C to' the program station. As the subscriber has already hung up'his receiver' the marginal relay LR will'not be energized and the relay 17 at the subscriberis Station, which was alsoy deenergized by hanging upthe receiver, will release the relay 18 so that the loud III speaking receiver' 11 and associated appara` gram transmission by throwing the key Il,

thereby` completing a circuit 'through the winding ct the polar relay PR, over the nornial contacts oil thorelay 18, over the make i contacts ot the lzey-l, over the line L. make contacts ofthe relayV 12, jack J', plug l and through the windings oi" the marginal relay LR. 'lhereladv LR is not energized over this circuit as insuliicient current flows through the high resistance Winding of the polar relay 13R. The latter relay, upon the other hand, is not eitectively energized because the current flow is not in the proper direction to shittits armature. The circuit is now in such condition that the loud speaking receiver 11 Will be actuated by the currents transmitted from the broadcasting station. During this condition of the circuit a busy tone is applied over the lower front contactotf the relay 12 to the sleeve of the jack J at the regular switchboard to inform the operator that the line is being used for entertainment purposes. Y

It, While the line is thus Ain use, a suiiciently urgent call should come into the central switching otiice for the line L, the ope 'ator at the jack J may disregard the busy tone and insert the plug of the cord C in the jack, which thus completes a circuit over the sleeve ot the jack J through the cut-oil relay COR. The cut-otl'A relay at its right-handf contact opens a circuit of the marginal relay 1.2, which isv at once deenergized and disconnects the line L from the program station over the jack J and connects the line to the jack J for receiving the incoming call. The direct current now being supplied from the cord circuit C is in such a direction as to actuate the polar relay PR to close the cir .ing circuit will be established to the central ollice. Direct current romthe central otice battery flowsthrough the cord circuit over the-subscribers line and through the relay v17, this relay being energized as long as the receiver is removed from the hook. The relay 17 completes a circuit of the relay 18, which disconnects the program receiving apparatus from the line independently of the key K, and at its right-hand Contact opens the locking circuit of the relay 16, which is restored-to normal. At the end of the conversation, the subscriber may hang upV his receiver, thereby giving the usual disconnect signal and deenergizing the .relay 17, whichl (if key K has not been restored) again connects the polar relay PR, to the line. Tliecurrent through the polar relay is in such a direction as lo attract its `arnniture and thereby complete a circuit to energize and lock up the relay 1o. As soon as the operator withdraws the plug of 'the cord C treinv the jack J, the cut-oit relay CGR is deenergized, thereby causing the relay 12 to be energized and again connect ythe line L to the central program station over the jack J. Thedirection of the battery current over the line L is now reversed so that the. armature of the polar relay PR iialls'oii: but -relay 16 remains locked up. In order that the communication from the program station may be again received the key K should be restored to unlock the relay 16 and should then be again actuated.

It, While the line is being used for receiving the distributed information, the subscriber should desire to use the line tor establishing a telephone call, the receiver may be removed from the hook, thereby again cnergizing the relay 17 and, owing to the decreased resistance through the telephone set, energizing the relay LR in the cord circuit C. The relay 17 actuates relay 18 to disconnect the program receiving equipment in dependently of the key K. The relay LR', on the other' hand, shifts its armature so that the circuit of the marginal relayy 1Q nou7 passes through the high resistance letihand yWinding of relay LR. This causes the marginal relay 12 to be deenergized, thereby disconnecting the line L from the j ack J and connecting it to the jack J. T he circuit of the line relay LRy is now completed so that theoperator at the regular switchboard will be called and may establish the desiredY connection lin the usual manner through the cord lcircuit C. The insertion of the plug P of the cord C in the jack J causes the cut-olii relay COR to hold open the circuit'otl the marginal relay 12V and release relay LR. At the end ci' the conversation, the subscriber may hang up his receiver, thereby restoring the line to the condition for program reception in the manner already described.

Then the subscriber no longer desires to receive the entertainment service he will simply restore the key -K, thereby disconnecting the loud speaker and associated apparatus from the line. The line will still remain connected to the program station over the jack J', however, until the plug P is Withdrawn from the jack J. This will ordinarily take place at the end of the contract period Where a definite' period of serv ice is previously arranged for, otherwise the subscriber may have the connection to the program lstation taken down by calling the lregular operator at the jack J in the same manner as when a telephone call is initiated with the program equipment still connected. The operator, upon beingy lnformedthat the Vprogram connection is desired to be taken y special multiple, regardless of whether or not the subscriber has hung up his receiver or the cord C disconnected. The general arrangement of the apparatus is similar to that of the apparatus disclosed in-Fig. 1 and the detailed differences will be clear from a description of the operation of the circuit which is as follows.

Assuming that the subscriber Vdesires to receive the entertainment service, the receiver at station A will be removed from the switchhook, thereby energizing the marginal line relay LR, which completes a circuit for the line lamp. The operator then inserts theplug P of the cord C in the jack J, thereby energizing the cut-off relay COR, which disconnects the line relay LR, and extinguishes the line lamp. Upon ascertaining `that a program connection is desired,

' the operator may call the program operator at the special position over a call wire, notifying her to insert the plugP of the cord circuit C leading to the desired program station in the jack J of the line L. Upon insertingthe plug P in the jack J a circuit over the high resistance .relayv 12 is completed from ground, through the winding of said relay, over the sleeve contacts of the jack J and the plug P', 'over the lower back fcontact of relay 12, right-hand back contact of yslow release relay 25, back contact of marginal relay 26 and through the winding of relay 26 to battery. Marginal relayv26 will not be energized in series Vwith* the high resistance relay 12. lRelay 12, on the other hand, will not be energized.

when in seri-es with the high resistance winding of the relay- COR, but the latter relay is short-circuited during the condition above described, over the contacts of relay 12 and relay 25. Therefore, the relay 12 is energized and disconnects the line Li-om the jack Jv and connects it to the jack J so that the program station is now associated with. the line. The relay 12 also completes Y a circuit over its lower front Contact for the short-circuited over kits back left-hand contact and over the right-hand front Contact of the cut-oli relay COR. Assuming, howv As soon asY the circuit from the program,

station to the subscribers line is completed,

as previously described, anY energizing'circuit tor the marginalrelay LR and the special relay SR will be completedthrough the subscribers set, and both of these relays Y will be energized as well vas the lrela-y 17 of the subscribers set, provided the subscriber has not already hung up. The latter relay, by energizing relay 18, maintains the loud speaking receiverand associated equipment disconnectedfromthe line independently of the key vl. The'energization or' the niarginalV relay LR maintains a short circuit about the winding oi the relay 25, so that the latter'relay is not energized by the Special relay SR. The special relay SR completes an energizing circuit for the relay 28, however, over a circuit ,from ground through the right-hand front contact of relay SR, winding'of relay 28, lefthandjback contact ot' relay 25 and over the right-hand front contactof relay LR to battery. Relay 28, upon being energized, completes a short circuit 'for the relay COR over its front contact independently of the righthand back vcontact of the slowfreleaseirelay 25. The subscriber may now `act-nate the key K and thereafter hang up his receiver. Upon hanging up the-receiver, the relay 17 will 'be deenergized and the loud speaker 11 Vand associated apparatus will be connected to the lineover the contacts of thekey K. rlhe marginal relay LR will now be re leasedV because of the high resistance path through the polar relay PR and will remove the Short circuit from the winding of the slow release relay 25. The special relay SR will, however, remain energized in series with the high resistance winding of the polar relay PR and over its righthand front contactl completes a circuit through the windings oit relays 28 and 25 in series so that both relays are energized. The short circuit about Vthe winding of the cut-olip relay COR', which is opened by the energization of the relay 25, is closed at another point, however, by the front contact of relay 28 so that the relay COR is not energized. With the circuit in this condition the transmission from the program circuit passes directly over the line L to the subscribers station and operates the loud speaking receiver 11. The direction of current iioiv through the windings of the relays LR and SR is, of course, in such a direction as to prevent the operation ot the polar relay PR.

lf, While the line is thus in use, a sutliciently urgent call should come into the cen-Y tral switching oi'hce for the line L, the operator at the jack J may disregard the busy tone on the sleeve or the jack and insert the plug` ot the cord C in the jack, thus operating the cut-ott relay COR. The cut-off relay at its right-hand front contact connects ground over the lett-hand front contact ot the slow release relay 27 to the sleeve ot' the jack J', thereby short-circuiting the Winding 'of the relay 12. The relay 12 is thereby deenergized and disconnects the line L :trom the jack J and again connects it to the jack J. jack J is now directly connected to ground, the marginal relay 26 is energized over a circuit 'from battery, through the Winding et said relay, over the back contact ot' said relay, over the front contact of relay 28,Y

lower back contact oi relay 12, sleeve con-V ductors of the plug P and the jack to ground. Relay 26, upon being energized,

at its left-hand Contact opens the short cir# cuit path about' the Winding of the relayy COR, which is at once energized in series with the relay 26 to connect battery to the disconnect lamp 30 Vand to the Winding of the relay 12. Relay 12 disconnects the program station from the plug P of theV cord C and the disconnect lamp 30 indicates to the operator at thev program multiple that the cord circuit C should be disconnected Jfrom the jack J. The relay 12, by openingthe trunk circuit, causes the re'- lay SR to be deenergized, thus restoring the relays 25 and 28 to normal. As soon as the operator withdraws the plug P the circuit through the relays COR and 26 is opened, thereby causing the armatures of these relays to fall ott'. As a consequence, the circuit or" the relay 12 is opened and the circuit is restored to normal.

ln the meantime, as soon as the relay 12, by allingoti, connected theline L to the jackJ, the direct 'current through the cord circuit C passes over the line L in such a direction as to actuate the polar relay PR,

which in turn completes a circuit of the relay 16 and disconnects the loud speaking receiver 11 from the transformer 14. vThe subscriber at station A', in response to a ringing signal, 5 removes his receiver from the sivitchhook, thereby energizing relay 17, which in turn completes a circuit for the relay 18 to disconnect the receiver 11 and transiorn'ier 14 from the line circuit` independently of the key. K. Atthe terminationv of the rcoiiversation, the subscriber at station A may signal the operator atthe jackJ Since the sleeve ot the Y connection with the original setting up of the programconnection. i

1f, While the program connection is set up and in operation, the subscriber at the station A should, for rany reason, desire to make an ordinary telephone call, he Will remove liis receiver from the switchhook,

thereby reducing the resistance through the circuit of the relays LR and SR so that the marginal relay LR is operated as well as the relay SR. The relay LR completes a circuit for the relay 12 from battery, over the front contact or the relay LR', lett-hand front contact of the relay 25 and through the Winding. of the relay 12 to ground. rllhe relay 12 disconnects the program station from the plug P and hence from the line L. At its lower contact the relay v12 opens a short circuit about the Windiiigvoi the relay COR, which is energized and con-,J nects battery to the disconnect lamp 30 and also the relay 12, Which willnoiv beheld up independently ot the contact yof the relay LR, Which falls orf upon the opening of the cord circuit 'by the relay 12. The inclusion of the high resistance of the relay COR iny the sleeve circuit causes the marginal relay 12 .to tall oit and connect the line L to the jack J. The operator at the `program multiple,'upo`n observing the disconnect signal, Will Withdraw the plug PWi'rom the jack J and restore. the apparatus of the cord'circuit C to normal.` In the meantime, the connection'ot the lineL to ythe jack f the operator at the answering jack J that connection is desired. The telephone connection will noiv be established in the usual ina-nner. At the end ot the conversation, the subscriber may, by callingvthe operator at the Jack J, order the program connection reestablished in the manner already described.

lf, While the program circuit is in opei= ation, the subscriber desires the lfirogramy connection taken down, he may simply restore the key K to normal, thereby disconnecting the receiving apparatus from the line and opening the line circuit, The relay SR at the cord` circuit C Will be at once deenergizedy and ivill open a circuit of the relays 28 and 25; IRelay 28 immediately falls oill and opens a short circuit aboutithe kcut-off relay COR before 'the ,alternative shortcircuitis'completed over the back co'ntact or' therelay .25 the latter relay beine' n a I y ze slow. to release. Alhe relay CGR is consequently energized and connects battery tothe rdisconnect lamp 30 and the relay 12. The

relay 12 disconi'iectsthe program station yie from the plug P and hence frointhe line L7 and yatits lower Contact opens rthe short circuitabout the relay COR independently of eitherlthe relayrQS or, 25, so that when the u latter relaydeenergizes the relay COR ywill still remain energized. The operator, upon observing the discoiinectsignal, will Withdraw the plug P, thereby ldeenergizing the relay COR and the relay 12 .to restore the Acord circuit to' normal. The relay 12'is` also deenergized'` when the sleeve` circuitv is opened by `withdrawing the plug'lyand 'establishing the normal connectionA from the line L to thev answering jack Jl y Fig. 3 shows an arrangement adapted for use in conection with step by step machine switching offices. The circuit of Fig. 3 isksoA arrangedthat the subscriber may dial a cer.`- tain code number when he wishes to receive y the program service and Will thereby beconnected by the mechanical switches. to termi- .nals of the multiple bank, which are connected througl'i a transformer 13 to the program station D, asv indicated. Differei'it code numbers may be assigned to vdifferent programtiunks and the subscriber may thus elect any particular program. Relays LR and SRare connected with the tipand ring y conductors ofthe selector bank,` the former .y being marginal and operatedonly through the loW resistance of the` subscribersv set when the receiverl is olfthehook. Auxiliary relays 31 and 32 are also provided. for con-A trolling the busy condition of the sleeve cir- `cuit and yfor performing certaiiifunctions incidental yto the release of the connect-101i.y

Further details of the 4circuit -Willbefclear yfrom a description of lthe operation'vvhiclr l is` as follows.

Y 'Assuming that the subscriber at stationA desires a connection to the program station, the receiver will y be removed from the l switchhook and the dial 19 :Will be inanipu# lated in a Well knownfmanner to operateV the y y stepby step switching machinery to connect the subscribers line L vto the tip andrin'g conductors of tlieterminal banlnwhich are connected to the prograinstationD through the transformer 13. As soon as this connection' is established' the .relays LR. and.

SR arelOOth energized over'the line circuit L and through the low resistance of thesubfrom being energized overthe lower'front contact ofrelay SR. v(Alfround is connected toy over the upper contact of therelay vSRl and f.. over the back contact of tlierelay 32t-o theV i sleeve conductorto hold the selectorl and to prevent other selectors frein making con.-V nection tov the 'selected terminals' of the selector bank. i

, `Af`ter dialing thecode forestablisliing the weeen connection jiistdescribed, they subscriber will operatehis connecting key K and hang up. his receiver. The relay LR, Abeing niar, ginallwill not be energized through the `high resistance of the polar relay PR but thel relay SR will remain energized. Relay` LR noon beine' released fremoves the short circuitfrom the `Winding ofthe relay 31 Whichfi's at. once energized .andlconnect-s ground to the sleeve circuitover theback Vcontact ofA the relay. 32 independently of the sleeve terminalover the upper front contacty of the relay SR and opening the circuit of the relay.. 31, Which falls off and disconnects groundV fromthe sleeve terminal `.over its left-handcontact. The mechanical switches. are at onceV released. and the ap.

paratusfis all restore/dito normal.

lf, in-

stead of disconnecting `the program station`r by restoring` theiconnecting key, ,the Subscriber desires to ymake an ordinarygtelephone connection While the program connection isstill establishedythe.subscriber simply removes the receiver from the switchhook, thereby energizing relay LR in addition to the relay SR and also con'ipletingvthe circuit ,for tlierrelay 117 at the subscribers tion. Therelayl' closes the circuit ofthe relay 18 .to disconnect the loud speaking re ceiverfand associated apparatus infthe same manner as `described in' coniiectioirwith the previous circuits. p relay LR connectsl battery over ktheupper front contactfofsaid lrelay and over the rightfliand front'contact'of frelay 31 to the Winding of therelayl, Whichis energized ductor of the. selector bankg'ltlius releasing the relay SR. The connectingkey K at the subscribers station having connected the i loudspeakiiig receiver 1l: to Vtheline through cause ofV thediiection of current flow sup- The energization of the and disconnects ground fromthe sleeve con-1 es, in .-ieleasing, open thefcircuits ofthe tip Y aiiidfring conductorslrelays SR." and LR are deen'ergiz'ied, thereby openingy theciishown) associated with the line L: Will now..v

seize a selector, runk in theV saine vmanner cuits of the relays 31 and 32,'which are re-` f#- as'yif,` thewreceiver had just -been removed;

fromnthehookY fortheliist tiineandthe me Y subscriber may manipulate his dial to obtain the connectiondesired. With this arrangement, the line will test busy because ot the ground connection through the sleeve and all incoming calls to the subscriber will be excluded so long as the program service is being received.

It will be obvious that the general principles herein disclosed may be embodied in other and different organizations widely ditferent trom those illustrated without departing from the spirit of the invention as detined in the appended claims.

lVhat is claimed is:

l. In a telephone system, a plurality of telephone lines terminating at a central otlice at one end and a subscribers station at the other, a telephoneset at each subscribers station, an operators position at the central oliice having switching ,means whereby any one ot said lines may be interconnected with another telephone line tor telephonie intercommunication, a program transmitting station, connections independent ot said operators position extending irom a plurality of lines to a second operators position, and lswitching means at said second operators position tor individually interconnecting a plurality ot said lines to said yprogram station at the same time over said connections.

f2. In a telephone system, a telephone line terminating Vat a central ottice at one end and a subscribers station at the other, a telephone set at the subscribers station, an operators position at the central oihce having'switching means whereby said line may be interconnected with other telephone lines for telephonie intercommunication, a program transmitting station, a second operatoris position, switching means thereat :tor interconnecting said program station with said line,and means to disconnect said line at said second operatorie position from the switching means at said second operators position when a connection is established tov said line through said first operators position.

3. In a telephone system, a telephone line terminating at a central otice atone endv and a subscribers station atfthe other, a telephone set at the subscribers station, van operators position at the central ottice having switching means whereby said line may be interconnected with other telephone lines for telephonie intercommunication,` program transmitting station, aV second operators position, switching means thereat tor interconnecting` said program station with said line, means to disconnect aid line from the switching means at said first operators position when said program station is connected to said line through said second operators position, and means responsive "to an incoming call at said Vtirstoperators position to disconnect said line trom said 'second operators position and again connect it to said tirst operators position.

4. In a telephone system, a telephone line terminating at a central oliiee at one end and a subscribers station at .the other, a telephone set at the subscribers station, an operators position at the central olce having switching means whereby said line may be interconnected with other,telephonelines for telephonie intercommunication, a program transmitting station, a second operators position, switching means thereat torA interconnecting said program station with said line, means to disconnect said line trom the switching means at said first operators position when said program station is connected to saidksecond operators position, and means responsive to a call outgoing from said line to disconnect said line trom said second operators position and again conneet it to said first operators position.

5. In a telephone system, a telephone line terminating at a central oiiice at onefend and in a subscribers station at th-e other, a telephone set at said subscribers station, program receiving means atsaid subscribers station, an operators position at the central oltioe having switching means tor interconnecting said line withother telephone lines tor telephonie intercommunication, a program transmitting station, a second operators position having switching means thereat for interconnectingsaid program station with said line, and means to connect said program receiving means at the subscribers `station with said line and said program stati-on at the central office with said line over the switching means at said second operators position when the line is not being used for ordinary telephonic purposes.

6. In a telephone system, a telephone line terminating at acentral office at one end and in a subscribers station at the other, a telephone set at said subscribers station, program receiving means at saidv subsoribers station, an operators position at the central oltice having switching means for interconnecting said yline with other telephone lines :tor telephonie intercommunication, a program transmitting station, a second operators position having switching means thereat for interconnecting said program station with said line, means to connect said program receiving means at the subscribers station with said line and said program station at the central oliice with said line over the switching means at said second operators positionwhen the line is not being usedl for ordinary telephonic purposes, and means tor disconnectingy said line trom said lirst operators position wheny a connection is established to said second operators position.

7. In a telephone system, a telephone line terminating at a central office at one end irl Y a" subsoribers "station at the othei end,v

andi in a suloscrih'ers stationat'the other, a telephone 'set' atfsaid suhscrihers station,` program receiving .means at saidsubscribcrs station, an operators positionfatthe central oitice having switchingmeans 'for interconnectingsaid'line with4 otherl telephone lines `l for telephonie interconimunication, aprixv` grani transmitting station, a. second'operators position'having switching means therelattor interconnectingsaid program station with said line, means'toconnect said program'receiving means at the subscrihers station with sai-d line and said program statioir at ythe central otiice with said ine over the vvswitching*means `'at said second"operators position when the line is notfheing used tor ordinary telephonie purposes, meanstor disconnecting said line from said vrl'irst operan toi-s position. when a connection isestalo-f lished to said second operators position, and nieansresponsive to an incoming call to disconnect said lineV from t-he switching means at said second operators position and again piogram` receiving means at said subscribersV station, an operators position' at the` central ofiice having switchingmeans tor interconnecting .said-line with -other tele'- phonel lines for telephonie intereommunication, a program.transmittingstation, a sec# ond operators `r`position having switching means thereat it'oi' interconnecting said program ystation with.' saidline, means to connect said program receiving meansjat ythe subscribers station withsaid line and said program station atfthe central oiiice with .said line over the switching means at said second operators positionwvhen theline'is not being used for ordinary telephonie pui'- poses, means for disconnecting said line from said i'irst operators position when a connection is established to said second operators position, and means responsive to a calloutg-oing from said line for disconnecting said line 'from the switchingfmeans at the second operators position and again i connecting` it to the switching'means at said `firstoperators position.

" 9; In a telephone system, a telephone line terminating at a central office at one end and switching points atwhich other'lines terminate, other switching` points to which a pro grani transmitting station isconnected, `link circuits for interconnecting lines in pairs through said first mentioned switching points'l or for interconnecting plurality or lines lto said program station through said second sition.

mentioned switching points, and means re` sponsive to an incoming call forsaid irst'V mentioned` line when said line is vconnected to said program station for disconnecting the'line from the program station and connecting it to the calling vtelephone `iine. Y

l0. ln a telephone system, a telephone line 'tei'n'iinat-ing at a central oiiice at one end .Y andv a subscribers station at Vthe Yother end,

lswitching points `mtivhich other linesl ter minate, other switching points to which a" 'ing points or torinterconnecting a'plurality ot lines to said program station through said second mentioned switching points, and

means responsive to a call outgoing from said iirst mentioned line when the line isV connected with said program stationior disconnecting the yline from said Aprogram station and connecting it to the called line. l

ll. in a telephone system, telephone lines teri'i'iinating at a central oiiiee at one end and a subscribers station at the other, a telephone set at each suhscribesstation,` an operators position at the central'oiiice having-"switching means whereby any one of said lines may be'interconnected with an-r other telephone line for telephonie communication, a program transmitting station, a second operators position at which said` program station may he connect-ed toa p`lurality of said lines, means to signal the operator at .said sec-ond position, and means `to defeat the. connection of a given `line ,through said second` position when said line is connected to another line atsaid ii'st po- 12. In a telephone system, telephone lines terminating at a central oiiice atoone end and a subscribers station at the otheig'a telephone set at each subscribers station,anoperators position at thecentral oiiice'heving switching means whereby any one 'of said lines may he interconnectedwithanother telephone line for rtelephonic inter-"'-V communication, a program transmitting sta tion, a second`operatoi"s position at whichVY said program station may be connectedtoa plurality of saidlines, means to signal the operator at said secondv position to "disconf nect the programstation romla givenfline,

land vmeans. to defeat the connection oi" said Q ln testimonywhereofwe have signed our November 1922. y

JoiiN ii. frooiinif.,y i HENRY ii. Pirates;-

l names to this speciticationthis 10th oit i 

